In an electric guitar, e.g. a Les-Paul-type of guitar, a string is passed through a string through-hole formed in a tailpiece attached to the surface of a body, the end of the string, called the ball end, is hitched into the opening of the string through-hole, the other end of the string is wound around a peg in the head side, and the string is pulled taut with a predetermined amount of tension. The bridge disposed on the head side relative to the tailpiece has a function as a fulcrum of string oscillation when the string is plucked, a fine-tuning function of intervals tuned with the peg, a function of adjusting the height of the bridge itself in order to adjust the height of the string from the fret board, and other functions.
Patent Document 1 discloses a string locking structure for an electric guitar that uses a tailpiece. In Patent Document 1, strings are passed through holes formed in a fixed plate of a tremolo block, the ball ends of the strings are locked in portions of large inside diameters formed in the rear ends of the holes, and the fixed plate functions as a tailpiece. The holes for passing the strings through the fixed plate are linear through-holes extending from the front surface to the rear surface. Patent Document 2 discloses a string locking structure using a bridge having an integrated tailpiece, in which a string through-hole extending linearly in the longitudinal direction of the guitar is formed in the bridge.